Sharpening device



`gan. 12%, 1941i A. P. KoMowl SHARPENING DEVICE Filed Nov. 20, 1940 ginW ATTORN EYS Jan. 12, 1943.l

' A. P. KOMOW SHARPENING DEVICE Filed Nov. 2o. 1940 `s sheets-sheet 2INVENTOR.

ATTORNEYS l Jan.12,1943.. A. P. koMow 2,308,012

SHARPEN ING DEVICE Filed Nov. 20, 1940 s Smets-sheet 3 Fles.

v INVEFOR. v BY @lle/1f" ffm/w FIG-8,

ATTORNEY.r

Patented Jan. 12, 1943 f UNITED STATES PATENT lOFFICIE.

SHARPENING DEVICEr Application November 20, 1940, Serial No. 366,401

Claims.

My invention relates to a new and improved sharpening device for acloth-cutting machine of the reciprocating straight-knife type.

One of the objects of the invention is to provide a presser-foot whichcan be held at any desired adjusted height and which is turnedautomatically by the grinder-mechanism to the respective inoperative andoperative positions of said presser-foot without changing the verticaladjustment of said presser-foot.

Another object of the invention is to provide grinder-mechanism whichsupports the grinding stones and which is depressed by hand and which israised automaticallywhile theknife is rapidly reciprocated, `and whichis automatically disconnected from the motor Which actuates saidgrinder-mechanism, when the grinder-mechanism has been raised to its topand inoperative position.

Another object of the invention isto provide improved means whereby thegrinder stones are held above the top of the knife, in inoperativeposition, by manually releasable mechanism.

Other objects of my invention will be set forth in the followingdescription and drawings which illustrate a preferred embodimentthereof, it being understood that the above statement of the objects ofmy invention is intended generally to explain the same Without limitingit in any manner.

Fig. 1 is a side elevationof the improved device, the illustrations lofcertain of the parts having been omitted, in order to show certaininterior constructionv more clearly. In this view, the rack-bar 2| isshown in a position which is below its top position.

Fig. 2 is a front elevation of the device illustrated in Fig. 1.

Fig. 3 is a sectional View on the line 3 3 of Fig. 1.

Fig. 4 is a sectional view on the line-4 4 of Fig. 1, with the rack-barin its bottom position.

Fig. 5 shows the parts illustrated in Fig. 4, when the grinding stonesare in their top inoperative position, in which said grinding stones arespaced from each other. In this view, the rack-bar 2| is in its topposition.

Fig. 6 is a sectional View on the line B-x of Fig. 1.

Figs. 'I and 8 are respectively sectional views on the lines 1-1 and8--8 of Fig. 4.

Fig. 9 is a sectional view on the line 9.-9 of Fig. 6.

The cloth cutting machine itself. may be of any suitable or standardconstruction. The cloth cutting machine comprises a base I, a handle 2and 55 a motor casing 3. The knife 4 is of the usual type, beingprovided with a front cutting edge and alsowith a bottom cutting edge.Save for certain details which are necessary for the understanding ofthe invention herein, the mechanism whereby the motor in the casing 3reciprocates the knife 4 is not illustrated, as such mechanism isWell-known per se.

Fig. 2 shows the shaftr 5 of the electric motor in the casing -3. Thedisc 6 is keyed or otherwise suitably rigidly connected to the shaft 5.The p in I is connected off-center to the disc E, and the head 8 of aconnecting rod 9 is turnably mounted upon the pin 'I. The lower end ofthe connecting rod 9` is pivotally connected to the top of the knife 4.'This connection is not shown, as it is wellknown. The annular peripheryof the disc 6 is cut, in order to provide a Worm I0. This `worm I0 canmesh with a worm wheel II, Whose hub I4 is releasably xed to theturnable and vertical shaft I2. This shaft I2 is turnably located in thespecial bracket or housing I-I. The hub I5 of a bevel gear I6 is alsosuitably xed to the shaft I2, so that lthe worm wheel II and the bevelgear I6 turn in unison. The bevel gear lli-meshes With a companion bevelgear I'I, whose hub I8 is rigidly connected to a horizontal shaft I9. Asshown in Fig. 2, the shaft I9 is provided with a pinion 20, which mesheswith a rack 2|, which can be moved vertically up and down. The shaft I9is provided With a suitable bearing 22. which is fixed to the frame ofthe machine. The bracket H is mounted turnably upon the bearing 22, sothat saidr bracketH has a limited turning movement relative to the frameof the machine. The rack 2I is guided .in a suitable bore of the frameof the machine, independently of the bracket H, so that the movement ofthe rack 2| is always vertical.

The presser-foot 23 is pivotally connected by the lpivot pin 24 to theenlarged head 25 of the presser-foot rod 26. The rod 26 is provided witha vertical series of horizontal teeth 2l. The periphery of thepresser-foot 23 is provided with a pair of* recesses 28v and 29. Thehead 25 of the rod 26 has a vertical recess in which a compressionspring 30 is located. This spring 30 down- Wardly urges the ba1l'3Iwhich can interfit partially with either of the recesses 28 and 29. Thepresser-foot'23 `may thus beheld releasably in the full-line positionillustrated in Fig. 1, or in the broken-line position illustrated insaid figure. Rod 26 can be vertically adjusted by hand, and for thispurpose said rod 26 is provided with a nnger-hold33. "The rod 2vissuitably guided'in a vertical bore of the frame of the machine, so thatthe bracket H turns independently of the rod 26. The rod 25 can beadjusted so as to hold the presser-foot 23 at any desired height.

Conventional mechanism is used for this purpose. This mechanismcomprises the conventional handle 34 which is turnably mounted in thebearing 35 of the frame of the machine. When this handle 34 is turned,it turns the eccentric 35, which is rigidly xed to said arm 34. Theeccentric 36 operates a plunger 31, which actuates a latch which mesheswith the teeth 21. This conventional mechanism is located in a part ofthe fixed frame, and it is covered by the removable cover plate 38.

The grinder stones 33 and 4i) are of the usual cylindrical shape andthey are mounted upon shafts which are respectively perpendicular toeach other. The shafts of the grinder stones39 and 44 are connected tobracket-members, which are mounted on a bracket 43 which is rigidlyconnected to the rack 2i. Fig. '7 shows the shaft 45a of the grinderstone 45. This shaft 45a has a threaded end 4I, which is fixed to asuitable tapped bore of the bracket-member 42. As shown in Fig. 6, thearm or bracket 43 is suitably fixed connected to the bottom of the rack2|. As shown in Fig. '7, this arm or bracket 43 has a squarecross-section. In addition to the bracket-member 42, said bracket 43 hasanother bracket-member 44. The bracket-members 42 and 44 are slidablyconnected to the bracket 43.

For this purpose the bracket 43 is provided with transverse bores 45 and45. The shank 41 of a screw ts snugly in a bore of the bracket-member42, and said shank 41 passes through the bore 45. The bore 45 iselongated, so that it guides the longitudinal sliding movement of themember 41 and of its associated bracket-member 42. The shank 41 passesthrough an elongated bore 43 of the bracket-member 44. The shank 49a ofanother screw 49 fits snugly in a -bore of the bracket-member 44, andsaid member 43a passes through the elongated bore 46 and it is locatedin the elongated bore 50 of the bracket-member 42. A covering washer 5Iis located between the head of the member 49 and the bracket-member 42.

A compression spring 52 is located in the 1ongitudinal 'bore 52a of thebracketmember 43, and the respective ends of said compression spring 52abut the Shanks 41 and 49. The spring 52 therefore urges the shanks 41and 49a. away from each other, thus urging the bracket-members 42 and 44to move in opposite directions relative to the bracket-member 43. Thesemembers 42 and 44 cannot turn relative to bracket 43, and they moverelative to bracketmember 43 only in a direction parallel to the axis ofbore 52a. Fig. 8 shows the shaft 39a of the stone 39, which is fixed `bymeans of its threaded end 365 to the bracket-member 44. The stones 39and 45 turn freely relative to their respective shafts 33a and 40a, theusual assembly means being provided for this purpose. These stones mayhave any shape.

The compression spring 52 therefore urges the grinder stones 39 and 45towards each other :and into operative contact with the vertical cuttingedge of the knife 4, during the grinding operation. This knife 4 isconnected to the usual knife-support 4a, which is slidably guided in avertical guide recess of the frame of the machine.

As shownrin Figs. 4 and 9, abent resilient latch member 53 is rigidlyconnected to the bracket-member 44. A companion resilient stud or pin54, of cylindrical shape, is connected to the bracket-member 42. Thispin 54 operates as a supplemental latch member.

When the rack 2| is moved upwardly, the head 56 of the stationary cam 55enters the space between the stud 54 and the corresponding adjacent partof the cam member 53. This is shown in Fig. 5, which also shows how thepin 54 and the adjacent convex portion of the cam member 53 releasablyengage the shoulders 51. This cam 55 is fixed to the frame of themachine. The shoulders 51 of the cam 55 releasably hold members 53and54.

In this position, the grinder stones 39 and 40 are separated from eachother, as shown in Fig. 5, and adjacent the top of the knife, even whenthe knife has been moved upwardly to its top position. Since the cam 55is rigidly fixed to the main housing of the machine, the bracket H canturn relative to said member 55.

A latch 58 is connected by a pivot pin 59 to the frame of the machine. Acompression spring 50 urges the latch 58 to the position indicated inFig. l, in which the extension 6| of said latch 58 engages a recess Glaof the housing H, sothat the housing H can be thus held, when required,in the operative position shown in Fig. l, in which the Worm I0 engageswith the worm gear H. This operative position is also shown in Fig. 4.

The rack 2i is provided'with a screw Whose head 52 projects laterallyfrom said rack. When the rack 2| is moved upwardly through apredetermined distance, the head 62 strikes the tail of the latch v58,thus releasing the housing H, which is then free to swing to theinoperative position which is shown in Fig. 5, in which the Worm wheelIl is out of mesh with the worm I0. The worm wheel II projects through aslot in the frame of the machine and a wall of said slot limits themovement of worm wheel I l, when housing H is turned. As soon as thelatch 58 releases the housing H, the reaction of the teeth of worm wheelI I against the teeth of worm I0 is sufficient to turn the housing H toits normal inoperative position which is shown in Fig. 5. Means areprovided for releasably locking the housing H in its inoperativeposition. These means comprise a latch 63, which is pivotally connectedat 64 to the frame of the machine. The compression spring 65 urges thelocking extension 66 of the latch 63 to enter the corresponding recess66a of the housing H, as shown in Fig. 5.

The top of the rack 2l is provided with a knob 61 which has a ange 68 atthe bottom thereof. When the rack 2l is manually depressed, the ange 68strikes the latch 63, as shown in Fig. 4, thus releasing the housing Hfrom the latch 63. The knob 61 also strikes the inclined branch of thespring 69, which is Xed to the housing H. The downward movement of theknob 61 therefore automatically releases the housing H from the latch63, and it also automatically turns the housing H to its operativeposition in which worm I0 meshes with worm gear Il. 'I'he housing isthen releasably held in this operative position by the latch 58. Thedownward movement of rack 2| rst moves head 62 away from latch 53.

Either of the bracket members 42 or 44 can be moved longitudinallythrough a limited distance, independently of the bracket 43. However, ifone of the bracket members 42 or 44 is thus moved 4relative to thebracket 43, the spring 52 causes the simultaneous movement of the otherbracket member. The grinder stones 39 and 46 can thus be moved relativeto each other, in order to separate them, and both grinder stones canalso be moved together in unison, relative to the bracket 43.

The operation of the device is as follows:

While the machine is used for cutting cloth, the rack 2| is held in itstop position, in which the head 56 of the stationary cam member 55 holdsthe stones 39 and 40 separated from each other. The housing H is thenreleasably held in the inoperative position which is shown in Fig. bythe latch 63. The stones are thus located upwardly relative to theknife, and the stones are laterally spaced from each other.

When it is desired to sharpen the knife, the rack 2| is forced down `byhand to its bottom position, while the electric motor in casing 3rapidly reciprocates the knife. The bottom position of the rack and ofthe grinder stones is illustrated in broken lines in Fig. 1. The knifeis thus ground or sharpened during the downward movement of the rack, assoon as the grinders are free to move laterally to operative position.

During this downward movement of the grinder stones, the presser-foot 23is turned automatically from the operative full-line positionillustrated in Fig. 1, to the inoperative broken-line position which isillustrated in said figure. The presserfoot 23 is held in saidbroken-line position, by means of the ball latch 3| and the recess 29.The knife 4 is rapidly reciprocated in the usual manner.

Since the worm I6 is now in mesh with the worm wheel Il, the rack 2|will be raised slowly while the grinders 39 and 4D are pressed againstthe opposite edges of the knife 4, in the manner shown in Fig 3. Thefriction between the edge of the knife and the grinder stones 33 and 40will turn said grinder stones upon their respective shafts. While thebracket 43 is moved upwardly from its bottom broken-line position whichis shown in Fig. 1, said bracket 43 will strike the nose 23a of thepresser-foot 23, thus restoring the presser-foot 23 to the operative andfull-line position which is shown in Fig. 1. At about the limit of theupward movement of the rack 2|, the head 56 of the cam 55 automaticallyseparates the grinder stones 39 and 4|] which are then held in saidseparated relation, adjacent the top of the knife 4. The rotation of thebevel gear I5 then automatically turns the housing H to the inoperativeposition shown in Fig. 5, in which position the housing is held, untilit is again necessary to sharpen the knife.

At the beginning of said downward movement of the rack 2| from it-s topposition which is shown in Fig. 5, the extension 66 of latch 63 is inthe recess 66a, so that housing H is held releasably in the inoperativeposition shown in Fig. 6. The head 62 is then in contact with latch 58,so that said latch is held with its extension 6| out of the recess Bla.When the head 62 is moved downwardly, the biasing spring 60 urges theextension 6| to enter the recess 6|a, but extension 6| -then cannotenter recess Gla, but said extension 6| is then spaced laterally fromsaid recess 6|a.

Immediately at the commencement of the downward movement of the rack,the resilient pin 54 and the hook part of the resilient member 53 arereleased from the shoulders 51, so that the stones are moved to contactwith the faces of the knife 4, during the downward movement of rack 2|and while the knife 4 is rapidly reciprocated by the motor.

At about the end of the downward movement of the rack, the knob 61strikes the spring 69, thus laterally flexing said spring 69, whichurges the housing H to its operative position which is shown in Fig. 5.The iiange 68 then strikes the latch 63, thus releasing extension 66from recess 66a, so that the flexed spring 59 turns the housing H to itsoperative position. The exten-sion 6| of latch 58 is moved into recess6|, thus locking housing H in its operative position. The shaft I9 isthen rotated, so that pinion 26 moves the rack 2| upwardly, while thereciprocation of the knife 4 by the motor is continued. At about the endof the upward movement of rack 2|, the head 62 strikes latch 58, thusreleasing extension 6| from recess 6|a. At about the same time, the cam55 separates the stones from the edge of the knife. The torque which isproduced by the pressure of the teeth of worm wheel against the teeth ofworm I6, then automatically turns housing H to `its inoperativeposition, in which extension 66 can enter recess 66a.

Ordinarily a single downward and upward movement of the grinder stonesrelative to the frame of the machine is suflcient to sharpen the knife.

Since the grinder stones are hield laterally spaced from each other bythe member 56, said grinder stones may then be located at the level ofor below the level of the top of the knife, when the knife is in its topposition or bottom position or intermediate said top and bottompositions.

The latches which respectively hold the bracket H in its operative andinoperative positions are of the snap type so that they automaticallysnap into holding positions, and the bracket H can be released fromeither of its positions, if

desired, by applying sufficient turning force to` said bracket.

I have shown a preferred embodiment of my invention, but it is clearthat numerous changes and omissions can be made without departing fromits spirit. For convenience I have described the device in the positionin which the knife reciprocates in a vertical path, but of course themachine could be held in any suitable position.

I claim:

1. A cloth cutting machine which has a frame, a'knife which is mountedto reciprocate relative to said frame in a vertical path, a rack guidedto reciprocate relative to said frame in a vertical path, said rackbeing spaced laterally from said knife, grinder members connected tolsaid rack' which contact with the opposite faces of the vertical cuttingedge of said knife when said grinder means are located between the topof the knife and the bottom of the knife, said grinder members laterallymovable to and fro relative to said faces of the cutting edge of theknife, spring means connected to said rack and urging said grindermembers towards each other to contact with said opposite faces, saidrack having vertically superposed teeth, a pinion in mesh with saidteeth, a first horizontal shaft to which said pinion is connected, saidfirst horizontal shaft having a bearing which is connected to saidframe, a first bevel gear connected to said first horizontal shaft, abracket turnably mounted on said rst horizontal shaft and rockablerelative to the frame to respective operative and inoperative positions,a second shaft mounted in said bracket, said second shaft having asecond bevel gear in mesh with said first bevel gear, a motor- `movablyto said frame which holds said bracketreleasably in operative position,a secon-d latch connected to said frame which holds said bracketreleasably in inoperative position, a memberl projecting laterally fromsaid rack which actuates said first latch to release said bracket whenthe rack is in its upper position, another member connected to said rackwhich actuates said second latch to release said bracket when said rackis moved downwardly from its upper position, said last-mentioned memberand a cooperating member on said housing which turns said housing to itsoperative position when the rack is moved downwardly.

2. A cloth cutting machine comprising a frame and a knife which ismounted to reciprocate to and fro relative to said frame in apredetermined path, a supporting rod guided in said frame to move to andfro in a path which is parallel to the path f movement of the knife, abracket connected to said supporting rod and extending laterally fromsaid supporting rod towards said knife, a first bracket member, a secondbracket member, means slidably connecting said bracket members to saidbracket and permitting each bracket member to move laterally to and frorelative to said supporting rod, a first shaft connected to the firstbracket member and movable in unison therewith, a second shaft connectedto the second bracket member and movable in unison therewith, each saidshaft being laterally movable relative to the other respective bracketmember, said bracket having a longitudinal bore through which saidshafts pass transversely, a spring located in said bore and also locatedbetween said shafts, said spring urging said shafts away vfrom eachother, grinder stones respectively turnably mounted on said shafts andmovable into contact under the action of said spring with the respectiveopposite faces of the longitudinal cutting edge of said knife.

3. A cloth cutting machine having a frame and a knife which is mountedto reciprocate vertically relative to said frame, a vertically movablesupporting rod which is spaced laterally from said knife, saidsupporting rod being downwardly manually movable, a lateral bracketconnected to said supporting rod, supplemental lateral bracket membersslidably supported on said lateral bracket, each bracket member having agrinder connected thereto, spring means which urge said shafts towardseach other to bring said grinders respectively into contact with therespective opposite faces of the vertical cutting edge of said knife, acam fixed to said frame, cam-members respectively fixed to said bracketmembers, said cam members being spaced laterally from each other whensaid grinder members contact with said faces, said cam being located andshaped to enter the lateral space between said cam members and to movesaid cam members away from each other when said supporting rod is raisedto a predetermined position, a motor driven shaft adapted to be coupledto and to be uncoupled from said supporting rod, said shaft raising saidsupporting rod when said shaft is coupled to said supporting rod, meansautomatically uncoupling said shaft from said rod when said rod is at apredetermined height.

4. A cloth cutting machine having a frame and a knife mounted toreciprocate vertically relative to said frame, a supporting rod spacedlaterally from said knife and mounted to reciprocate vertically, anactuating shaft mounted in said frame, a second shaft having means whichactuate said supporting rod, a bracket turnably connected to said frame,said bracket being turnable to an operative position and to aninoperative position relative to said frame, said bracket havingcoupling means which couple said actuating shaft and said second shaftonly when said bracket is in operative position, said supporting rodhaving grinders which are movable to contact respectively with theopposite faces of the longitudinal cutting edge of the knife, a movablelatch which holds said bracket releasably in said operative position,said supporting rod having a member which holds saidV movable latch inrelease position when said supporting rod is in a predetermined positionin which said grinders are held spaced from said faces, means which holdsaid bracket normally in inoperative position, said supporting rodhaving means effective upon its downward movement to turn the bracket tooperative position. 5. A cloth-cutting machine of the type which has aframe and a knife which is adapted to reciprocate in a predeterminedlongitudinal path relative to said frame, a supporting rod which ismovable wholly independently of said knife and which is guided in saidframe to move toand-fro in a longitudinal path which is parallel to saidlongitudinal path of movement of said knife, said rod having a pair ofshafts connected thereto, grinder stones respectively turnably mountedon said shafts, said shafts and said grinder stones being connected tobe moved in unison with said rod when said rod is moved longitudinallyto-and-fro in said longitudinal path of movement of said rod, saidshafts being movable relative to said rod towards each other and awayfrom each other in a lateral path which is lateral to said longitudinalpath of movement of said knife, said shafts being also movable in unisonrelative to said rod in the same direction along said lateralpath,-spring means associated with said shafts and biasing said shaftsand said grinder stones towards each other until said grinder stonescontact with the respective opposite faces of the cutting edge of theknife, said spring means being laterally movable in unison with saidshafts when said shafts are moved in unison and in the same directionalong said lateral direction.

ALBERT P. KOMOW.

